Min Sampling Research Articles

Deep reinforcement learning optimization framework for a power generation plant considering performance and environmental issues

In the electric power generation sector, striking a balance between maximum power production and acceptable emission limits is a challenging task that requires sophisticated techniques. With traditional methods, this is an extremely complex issue due to the large number of process variables that are involved. In this paper, a deep reinforcement learning optimization framework (DRLOF) is proposed to determine the optimal operating conditions for a commercial circulating fluidized bed (CFB) power plant that strikes a good balance between performance and environmental issues. The DRLOF included the CFB as an environment created from over 1.5 years of plant data with a 1 min sampling time which interacted with an advantage actor-critic (A2C) agent of two architectures named ‘separate-A2CN’ and ‘shared-A2CN’. The framework was optimized by maximizing electric power generation within the constraints of the plant’s capacity and environmental emission standards, taking into consideration the cost of operations. After training, the framework of the separate-A2CN architecture achieved a 1.97% increase in electricity generation and 1.59% emission reduction for NOx at 14.3 times lower computational cost. Furthermore, we demonstrated the framework’s flexibility, adaptability and lower computational burden by carrying out different test scenarios which demonstrated the effectiveness of the DRLOF. The findings of this study are not limited to the CFB power plant but can be extended to other chemical processes and industries. This approach minimizes the need for costly experiments, online optimization challenges and associated customizations. • Multi-objective optimization of CFB power plant with deep reinforcement learning. • Objective formulation considered power, fuel, reagent and environmental standards. • Two main reinforcement learning architectures were analysed for better CFB results. • Improved performance of CFB by 1.97% power increase and 1.59% emission reduction. • The framework’s generality, adaptability and computational efficiency were tested.

Morphological, ultrasonic mechanical and biological properties of hydroxyapatite layers deposited by pulsed laser deposition on alumina substrates

The development of biomaterials innovative compositions to be appropriate for hard tissue regeneration is vital and wished to improve the quality of life worldwide. In this work, using the pulsed laser deposition (PLD) technique, hydroxyapatite (HAP) was sputtered on a dense substrate of alumina at different times of exposure. The investigation of surface morphology indicated that grains of alumina were configured with dimensions of about 1.3–2.94 μm, while high content of porosity was observed. Moreover, the data revealed a significant plunge of surface roughness, whereas the average roughness decreased from 53 nm to 29 nm, and the maximum roughness valley depth decreased from 281 to 248 nm, recorded for 5 to 20 min of exposure time. The mechanical properties were examined non-destructively using ultrasonic waves, and it was noticed that the microhardness changed significantly from 24.7 ± 0.7 GPa to 27.2 ± 0.8 GPa for the compositions compared to 0 and 20 min samples. The attachment behavior of human osteoblasts cell line towards the obtained scaffolds was examined in vitro and prove that cells were proliferated and spread to cover the scaffold surface. This elucidates that manipulation of an innovative scaffold design can be executed based on tailoring of bioactive material (HAP) depositions on an inert biomaterial (alumina) to combine both mechanical and bioactivity, with less degradation rate.

Combined radio frequency and hot water pasteurization of Nostoc sphaeroides: Effect on temperature uniformity, nutrients content, and phycocyanin stability

Phycocyanin, the main pigment substance, is abundant in Nostoc sphaeroides. However, the thermal stability of phycocyanin is insufficient, so the processing and storage of Nostoc sphaeroides remain a critical problem. In this study, we have developed an innovative pasteurization technology: Radio frequency combined hot water pasteurization (RFCHWP) in order to improve the product quality of Nostoc sphaeroides. The results showed that RFCHWP technology exhibited good thermal uniformity and was effective in killing microorganisms in Nostoc sphaeroides. Compared to high-pressure steam sterilization (HPSS), heating by RFCHWP for less than 20 min had little effect on the color and texture of Nostoc sphaeroides samples. The ascorbic acid content of Nostoc sphaeroides decreased to 18.31 and 17.45 mg/100 g in the RFCHWP 30 min and HPSS samples, respectively. The phycocyanin content of Nostoc Sphaeroides in HPSS samples decreased by 32.89% compared with that in the RFCHWP samples. Phycocyanin was stable at a temperature of 50 °C and pH of 6–8. The results of this study showed that RFCHWP technology could be used as a bactericidal method for Nostoc sphaeroides with better product quality.

Hydrothermal vs. dilute acid pre-treatments: comparison of the biomass properties, distribution of pyrolysis products, and bio-oil characteristics

In this study, hydrothermal and acid pre-treatments were applied to improve the raw material properties of the bean pod. To evaluate the biomass as a fuel, it is superior to have low moisture content, high volatile matter, and carbon content. As acid concentration changed in acid washing and impregnation, different trends were observed in these contents. The optimum working concentration to meet all these properties was chosen as 1 M acid. In hydrothermal pre-treatment, as the temperature increased with constant reaction time, the moisture content of the biomass decreased while the amount of volatile matter was raised. According to the SEM, FT-IR, TGA, and preliminary and elemental analysis characterization results, the samples with high C and low O content after evaluating in hydrothermal pre-treatment at 190 °C for 20 min and hydrothermal pre-treatment at 150 °C for 20 min, washing with 1 M H3PO4, and impregnating with 1 M H3PO4 were subjected to pyrolysis process. When the tar yields obtained from impregnating with 1 M H3PO4 and washing with 1 M H3PO4 samples were compared, it was seen that the washing process gave a higher (19.56%) tar yield. In the pyrolysis experiments, the highest tar yield (22.18%) was achieved by using the hydrothermal pre-treatment at 190 °C for 20 min sample with a volatile matter content of 71.59%. Total volatile matter yields of pyrolysis were listed as (hydrothermal pre-treatment at 190 °C for 20 min) > (washing with 1 M H3PO4) > (impregnating with 1 M H3PO4) > (hydrothermal pre-treatment at 150 °C for 20 min). As a result, it can be concluded that the processes performed as hydrothermal method or acidic pre-treatment compared to raw biomass have an important role in obtaining the desired product distribution and properties in biofuel production.

Fusion of land use regression modeling output and wireless distributed sensor network measurements into a high spatiotemporally-resolved NO2 product.

Land use regression modeling is a common method for assessing exposure to ambient pollutants, yet it suffers from very coarse temporal resolution. Wireless distributed sensor networks (WDSN) is a promising technology that can provide extremely high spatiotemporal pollutant patterns but is known to suffer from several limitations that put into question its data reliability. This study examines the advantages of fusing data from these two methods and obtaining high spatiotemporally-resolved product that can be used for exposure assessment. We demonstrate this approach by estimating nitrogen dioxide (NO2) concentrations at a sub-urban scale, with the study area limited by the deployment of the WDSN nodes. Specifically, hourly-resolved fused-data estimates were obtained by combining a stationary traffic-based land use regression (LUR) model with observations (15min sampling frequency) made by an array of low-cost sensor nodes, with the sensors' readings mapped over the whole study area. Data fusion was performed by merging the two independent information products using a fuzzy logic approach. The performance of the fused product was examined against reference hourly observations at four air quality monitoring (AQM) stations situated within the study area, with the AQM data not used for the development of any of the underlying information layers. The mean hourly RMSE between the fused data product and the AQM records was 9.3ppb, smaller than the RMSE of the two base products independently (LUR: 14.87ppb, WDSN: 10.45ppb). The normalized Moran's I of the fused product indicates that the data-fusion product reveals more realistic spatial patterns than those of the base products. The fused NO2 concentration product shows considerable spatial variability relative to that evident by interpolation of both the WDSN records and the AQM stations data, with significant non-random patterns in 74% of the study period.

Investigating the influence of silver state on electronic properties of Ag/Ag2O/TiO2 heterojunctions prepared by photodeposition

Two series of Ag-TiO2 photocatalysts were prepared with the use of photodeposition method with variation of the irradiation time and precursor concentration. The obtained photocatalysts were studied by XRD, Raman spectroscopy, HR TEM, UV–vis spectroscopy, and low-temperature N2 adsorption/desorption method. It has been consequently found that the optical properties of the resulting catalysts differ significantly: the positions of surface plasmon resonance peaks red-shifted with the increase in precursor concentration. At the same time, optical absorption of the samples increases with both precursor concentration and irradiation time. Photocatalytic activity for the obtained catalysts was evaluated in decolorization of Rhodamine B with the use of Xe arc lamp (250 W) with and without λ > 420 nm light filter. Radical trap experiments have shown that the amount of both superoxide anions and hydroxyl radicals increased in full spectrum of the lamp, with the latter being absent in the reaction mixture during visible light photocatalysis. Comparison of different Ag-TiO2 catalysts has also been made, with 1-Ag-90 min sample being the most active in full spectrum, and 3-Ag-90 min demonstrating the highest conversion in visible light attributed to the increased generation of superoxide species on the surface of Ag clusters. Controversially, 1-Ag-45 min sample showed the lowest activity in full spectrum being surpassed even by unmodified TiO2, but reached the highest rate constant value in visible light. This effect can be related to advanced electronic interaction between Ag plasmonic nanoparticles and titania support in the presence of sensitizer compound, and the formation of Ag/Ag2O composite system on the surface of titania. Influence of the state of silver on photocatalytic activity and mechanism details is discussed with special attention to irradiation wavelengths.

A complementary unsupervised load disaggregation method for residential loads at very low sampling rate data

In this paper, low-resolution smart metering data analysis is applied to breakdown the load consumption for household appliances to facilitate the deployment of residential energy management solutions. A complementary NILM approach for smart meter data with a very low sampling rate is designed to disaggregate the energy consumption data for both household space thermal appliances and small appliances. The load disaggregation approach relies only on the general activity time usage data and public statistical data for appliance consumptions. A novel three-step disaggregation topology is applied to complement NILM problems. The first step is separating white appliances loads using existing NILM algorithms (commercial algorithm of WATT-IS company). The second disaggregation step couples an edge detection technique with a k-means cluster method to detect the ON/OFF event for heating and cooling loads, from the residual aggregated loads. Finally, a novel disaggregation approach using a dynamic fuzzy logic model and a predictive method is applied for the remaining aggregated loads to identify the ON/OFF event occurrence for small appliances. The proposed method is validated using French household dataset with 10 min sample data rates. Then it is applied to disaggregate the load consumption for Portuguese household dataset with 15 min sample data rates.

Diet composition and preferences of Bohor reedbuck (Redunca redunca ) in the compound of Alage College, Central Rift Valley of Ethiopia.

Numerous indices have been developed to compare use and availability of foods in field diets of wild ungulates. However, little attention has been given to laboratory analysis for comparing food preferences. To this end, a study aimed at investigating the diet composition and preference of Bohor reedbuck was conducted in the compound of Alage Agricultural College, Central Rift Valley of Ethiopia from 2017 to 2018 encompassing both dry and wet seasons. Bohor reedbuck is a medium sized horned antelope species endemic to Africa. Continuous focal animal observation was used to collect the data on plant species included in the diet of Bohor reedbuck. Focal individuals’ observation was carried out for 30 min in 10 min sampling interval during their active feeding period (early morning and late afternoon) over four different habitat types. The nutrient composition of plants consumed was determined using wet chemistry laboratory analysis. Bohor reedbucks consumed 15 species of plants; herbs comprised 94.3% of the foods they consumed. Digitaria abyssinica was the most preferred plant species with highest crude protein (23.75%) and less fiber (61.8% nitrogen detergent fiber and 27.8% acid detergent fiber). These findings suggest that food preference of Bohor reedbuck is determined by the nutritional content of the plant it consumed, since the area is more or less natural habitat in terms of plant species composition. For sustainable conservation of the species, there is a need to actively promote management of the plant species most preferred by the reedbuck to feed on.

Hybrid multi-stage decomposition with parametric model applied to wind speed forecasting in Brazilian Northeast

Wind speed forecasting is a challenging task, especially medium-term forecasting on 10 min sampling interval, due to the intermittent nature of wind. Several numerical methods were presented to improving wind speed forecasting accuracy, being the decomposition strategy reported as the key step to improve forecasting results, where the raw wind speed data is first decomposed into several patterns and then recomposed in a new time series. This can effectively reduce the uncertainty in the wind speed forecasting, leading us to believe that the precision of the forecast has a strong correlation with the preprocessing strategy, rather than with the forecasting technique. Based on this understanding, this paper combines two decomposition techniques, amplitude and frequency modulation-demodulation signal theory. The proposed decomposition approach is further combined with the parametric forecasting model named AutoRegressive Integrated Moving Average (ARIMA), resulting in a new ensemble learning method called Variational Mode Decomposition-Singular Spectral Analysis-AutoRegressive Integrated Moving Average (VMD-SSA-ARIMA). All forecasting results obtained by this ensemble are compared with those from the ARIMA. The ensemble results demonstrated stabilization of the forecasting errors. This indicates the ability of the proposed hybrid approach to decompose wind speed time series into uncorrelated components, reducing the errors from one up to a 12-steps-ahead forecasting horizon.

Contribution to the Process Development for Lactulose Production through Complete Valorization of Whey Permeate by Using Electro-Activation Technology Versus a Chemical Isomerization Process.

Whey permeate (WP) is a co-product of a cheese or casein production process that is regarded as an environmental pollutant because of its high organic load and is creating a major disposal problem for the dairy industry. However, it can be used as a suitable substrate to meet the increasing demand of producing a prebiotic lactulose through the isomerization of lactose present in the WP under adequate alkaline conditions. The goal of this study was to produce lactulose in situ of WP using electro-activation (EA) technology and compare the productivity of EA with conventional chemical isomerization at potassium hydroxide (KOH)-equivalent solution alkalinity in the feed medium. Electro-isomerization was conducted under different current intensities of 300, 600, and 900 mA for 60 min of EA with a 5 min sampling interval using 6, 12, and 18% (w/v) WP solutions. Chemical isomerization was carried out at the KOH-equivalent solution alkalinity to that measured in the EA solution at each 5 min interval using KOH powder as a catalyst. The outcomes of this study revealed that the production of lactulose using the EA approach was current intensity-, WP concentration-, and reaction time-dependent and produced the highest lactulose yield of 36.98% at 50 min of EA-time under 900 mA current intensity using 6% WP as a feed solution, whereas a maximum lactulose yield of 25.47% was achieved by the chemical isomerization at the solution alkalinity corresponding to that of the EA under 900 mA current intensity at 50 min in the 6% WP solution. Furthermore, a greater yield of lactulose was obtained using the EA technique for all reaction conditions compared to the chemical process at the equivalent solution alkalinity. Therefore, the results of this work suggest that the EA can be an emergent sustainable technology for achieving dual objectives of prebiotic lactulose production and concurrent valorization of WP using it as a feed medium.

Effect of Sampling Rate on Photovoltaic Self-Consumption in Load Shifting Simulations

Grid-connected photovoltaic (PV) capacity is increasing and is currently estimated to account for 3.0% of worldwide energy generation. One strategy to balance fluctuating PV power is to incentivize self-consumption by shifting certain loads. The potential improvement in the amount of self-consumption is usually estimated using smart meter and PV production data. Smart meter data are usually available only at sampling frequences far below the Nyquist limit. In this paper we investigate how this insufficient sampling rate affects the estimated self-consumption potential of shiftable household appliances (washing machines, tumble dryers and dishwashers). We base our analyses on measured consumption data from 16 households in the UK and corresponding PV data. We found that the simulated results have a marked dependence on the data sampling rate. The amount of self-consumed energy estimated with data sampled every 10 min was overestimated by 30–40% compared to estimations using data with 1 min sampling rate. We therefore recommend to take this factor into account when making predictions on the impact of appliance load shifting on the rate of self-consumption.

Trends in performance factors of wind energy facilities

This communication discusses the two parameters recently emerged as key performance indicators of wind energy facilities, the mean capacity factor over a year, and the standard deviation of the capacity factor from a high-frequency sampling of 1 min or less (the annual mean does not change if the sampling interval of the statistical population is every month or every minute; the standard deviation does). Both parameters impact the levelised cost of electricity. They permit to quantify the energy production by the specific facility. They also permit to attribute grid energy storage costs to the specific facility. This manuscript shows that the annual mean capacity factors of wind energy facilities are not improving in the U.S. with the year of completion. The average of the annual mean capacity factors of every facility operational in a given year is about 33% now in 2019 as it was in 2012. Additional to the flat trend in the average of the annual mean capacity factor, their variability is large at the individual facility level. With 5 min sampling frequency, the standard deviation of the capacity factor of an individual wind energy facility is about that same magnitude of the mean. This translates into a coefficient of variability—the ratio of the standard deviation to the mean—approaching unity. At the grid level, the variability of all the wind energy supply is still large and necessitates significant energy storage.

Concentration-dependent improvement of gelling ability of soy proteins by preheating or ultrasound treatment

In this study, effects of preheating or ultrasound treatment of soy proteins at different concentrations on the subsequent heat-induced aggregation and gelation behavior of these samples were investigated. Results showed that soy proteins with improved gelling ability were successfully obtained by preheating (100 °C, 30 min) samples at a protein concentration as high as 6% (w/v). The result was confirmed by increased storage modulus and viscosities of suspensions of the preheated soy proteins after reheating (100 °C, 30 min) at concentration of 10% (w/v). However, soy proteins with anti-aggregation and weakened gelation behaviors, as revealed by less increase in particle size and higher flow behavior indexes of tested suspensions at a concentration of 10% (w/v) after reheating, were obtained by preheating at lower concentrations (1%, 2%, and 4%, w/v). By comparison, all the samples pretreated by ultrasound at different protein concentrations showed greater gelling ability after reheating than the control sample. Results further revealed that soy proteins modified by preheating at lower protein concentrations showed greater loss of β-sheets structure and higher degree of unfolding. Whereas proteins pretreated by ultrasound showed lesser loss of β-sheets than the control sample. Findings of the study might provide useful insights on how the concentration of soy proteins during preheating or ultrasound treatment can be carefully controlled in order to obtain soy proteins with improved gelling ability.

Hydroxyethyl starch is an alternative washing solution for peripheral bloodstem cells products

Cryopreservation of hematopoietic stem cells (HSC) involves slow rate cooling in the presence of a cryoprotectant (DMSO) to avoid the damaging effects of intracellular ice formation. The infusion of DMSO with the thawed product has been related to adverse events. Reduction of DMSO content by washing the HSCs after thawing has been suggested as a method to avoid infusion-related side-effects. Albumin-dextran washing methods have proved useful in thawing HSC products. Dextran40 shortages prompted us to search for suitable alternatives. We report the results of a comparative study of the use of hydroxyethyl starch (HES) as an alternative to dextran40 for washing thawed HSCs products. A total of 10 HSC bags cryopreserved with 10 % DMSO were used. We conducted a paired study; one of the bags was thawed and washed with our standard washing solution (Dextran 40) and the paired bag with HES solution with a final HES and Human Serum Albumin (HSA) concentration of 2.4 % and 4.2 % respectively. Each final product was tested immediately after washing (sample 0’) and after 90 min (sample 90’) for total nucleated cells (TNC) recovery, acridine orange viability, viable CD34+ enumeration, and clonogenicity. No significant difference was found for any of the cell counts, viability tests, cell recovery, or potency. We can state that the washing solution based on 2.4 % HES and 4.2 % HSA is equivalent to that used in our routine practice. Therefore, we could use the solution with HES, paying special attention to the renal function of the recipient.

Enzyme-assisted glucose quantification for a painless Lab-on-PCB patch implementation

In the context of an integrated Lab-on-PCB wearable patch extracting interstitial fluid from the patient via integrated microneedles, the requirements from the integrated biosensing part are quite special compared to static glucose electrochemical biosensors. Hence, in this study, a fully PCB-integrated enzymatic glucose quantification Lab-on-Chip device is presented and evaluated considering these special requirements for such a patch implementation: a) range and limit of detection compatible with interstitial fluid glucose levels of diabetic patients and b) effect of sample flow rate on the biosensing platform performance. This work employs a chronoamperometric approach for glucose detection based on covalently immobilized glucose oxidase on PCB-integrated electrodes. The chronoamperometric measurements show that this platform exhibits μM range sensitivity, high specificity, and good reproducibility, and the assay can detect glucose from 10 μM to 9 mM with a lower limit of detection of 10 μM. The demonstrated detection range under continuous flow proved compatible with interstitial fluid glucose levels of diabetic patients. The sample-to-answer time of our Lab-on-PCB device is less than 1 min (sample delivery of few seconds and 20 s for electrochemical measurement), employing sample volumes of 50 μL in this instance. Increased flow rates substantially improve the platform sensitivity (1.1 μA/mM @0 μL/min to 6.2 μA/mM @10 μL/min), with the measured current increasing exponentially to the flow rate, as opposed to the theoretically expected much lower dependence. This work demonstrates the feasibility of Lab-on-PCB patches in terms of biosensing performance, paving the way for the first cost-effective, painless diabetes management microsystem.

The Spelling Errors of French and English Children With Developmental Language Disorder at the End of Primary School.

Children with Developmental Language Disorder (DLD) often struggle learning to spell. However, it is still unclear where their spelling difficulties lie, and whether they reflect on-going difficulties with specific linguistic domains. It is also unclear whether the spelling profiles of these children vary in different orthographies. The present study compares the spelling profiles of monolingual children with DLD in France and England at the end of primary school. By contrasting these cohorts, we explored the linguistic constraints that affect spelling, beyond phono-graphemic transparency, in two opaque orthographies. Seventeen French and 17 English children with DLD were compared to typically developing children matched for age or spelling level. Participants wrote a 5 min sample of free writing and spelled 12 controlled dictated words. Spelling errors were analyzed to capture areas of difficulty in each language, in the phonological, morphological, orthographic and semantic domains. Overall, the nature of the errors produced by children with DLD is representative of their spelling level in both languages. However, areas of difficulty vary with the language and task, with more morphological errors in French than in English across both tasks and more orthographic errors in English than in French dictated words. The error types produced by children with DLD also differed in the two languages: segmentation and contraction errors were found in French, whilst morphological ending errors were found in English. It is hypothesized that these differences reflect the phonological salience of the units misspelled in both languages. The present study also provides a detailed breakdown of the spelling errors found in both languages for children with DLD and typical peers aged 5–11.

Inhibitory effect of sugarcane (Saccharum officinarum L.) molasses extract on the formation of heterocyclic amines in deep-fried chicken wings

Sugarcane (Saccharum officinarum L.) molasses, rich in phenolic compounds, is an undervalued coproduct during sugar production. However, limited attention was paid to the inhibitory effect of sugarcane molasses extract (SME) on hazardous compound formation during meat processing. In this study, SME with high antioxidant activity was extracted and purified by many steps. Chicken wings were deep-fried for 2.5 min and 5 min after being painted maltose-water solution (1:1, v:v) with different SME concentration (0.2, 0.5, 1.0, 1.5 and 2.0 mg/L). The heterocyclic amines (HCAs) levels in deep-fried chicken wings were measured. Total HCAs levels in deep-fried 2.5 min samples were 4.51–8.04 ng/g, with the inhibition rates ranged 32.5–43.9% comparing with control. Likewise, total HCAs contents in samples after 5 min deep-frying were 26.2–37.4 ng/g, and the inhibition rates were 18.5–29.9%. In addition, the inhibitory effect of SME on HCAs formation followed significant dose-effect relationships, by correlation analysis between SME antioxidant activities and HCAs contents. But the weak correlations between SME antioxidant activities and relative total free radical contents demonstrated that the inhibition mechanism of SME was more complex than scavenge free radicals. It may be attributed to SME inhibit the HCAs synthesis via both free radical pathway and Maillard reaction pathway.

Effect of grain size and its uniformity on corrosion resistance of rolled 316L stainless steel by EBSD and TEM

The electrochemical measurements, Electron Backscattered Diffraction (EBSD), statistical analysis and transmission electron microscope (TEM) were used to study the effects of annealing after 92 % cold rolling on the corrosion behavior of AISI 316 L stainless steel in 3.5 % NaCl solution. The different heat treatment, which are 800℃-3 min, 900℃-3 min, 1000℃-3 min and 1000℃-1 h, have a significant effect on the corrosion resistance of the materials. Except for 800℃-3 min which was not completely recrystallized, the increase of grain size is beneficial to the corrosion resistance, but the uniformity of grains should also be considered. The high energy stress concentration at the grain boundaries and the distribution of intermetallic compounds pose challenges to the stability of passivation film. The final results indicated that the annealing at 1000℃ for 3 min samples with fewer grain boundaries and moderate grain size has the best passivation film quality and excellent corrosion resistance.

SO007OVERHYDRATION TREATMENT WITH COMBINED CRYSTALLOID AND COLLOID PD SOLUTION

Abstract Background and Aims Peritoneal dialysis (PD) fluids used colloid or crystalloid solutions to achieve ultrafiltration. Here we presented our clinical experience with the intraperitoneal (IP) use of mixed solutions (MS) (crystalloid plus colloid) to treat overhydration. Method We studied the kinetics of 4-hour single-dwell exchange using 2L MS in 3 different sessions. We analysed IP fluids and IP pressure at 0,30,60,120 and 240 min plus blood samples at 0, 120 and 240 min. MS kinetics were compared with standard 4-hour 3.86 % glucose (GS) exchange. MS composition. We modified a single-dwell exchange of 2L Icodextrin (Extraneal, Baxter®) by adding a continuous 50% glucose infusion (50g Glucose per 100mL) in an aseptic technique through infusion pump (42 ml/h) over 4 hours. Results MS exchange induced a progressive increase in IP pressure with an inverse decrease in IP sodium, without significant changes in IP glucose or osmolarity. MS exchanges were well tolerated without side effects (total 25 sessions). We did not observe any remarkable change in bloods samples during the MS exchange. The combination fluid enhanced net ultrafiltration (mean 1030 ml) compared with GS (650 ml). Although the net glucose dispensed was slightly higher with MS (79 g MS vs 77.2 g GS), similar net glucose absorption was observed (49.8 g MS vs 49.9g GS) and smaller maximum intraperitoneal glucose levels (1739 mg/dL at 120 min with MS vs 2695 mg/dL with GS at 0 min). GS induced a faster initial reduction in dialysate sodium concentration while MS maintained the sodium sieving over 4-hour dwell enhancing net ultrafiltration due to sustained IP glucose concentration. Conclusion The combination fluid could be a new strategy to enhance ultrafiltration in PD patients, leaded by colloid osmosis at the beginning of PD exchange maintained by crystalloid osmosis. Figure (A) Intraperitoneal kinetics of MIXED SOLUTION for IP sodium (Na+ PF), Osmolarity PF and intraperitoneal pressure. (B, C, D) Comparison between MIXED SOLUTIONS (black line) vs Glucose solution 3,86 % (gray line) intraperitoneal kinetcs for sodium (B), intraperitoneal pressure (C) and glucose (D).

Antibacterial and cellular response of piezoelectric Na0.5K0.5NbO3modified 1393 bioactive glass.

In the present study, the combined effect of addition of varying concentrations (10-30 vol%) of biocompatible piezoelectric Na0.5K0.5NbO3 (NKN) as well as electrostatic and dynamic pulsed electrical treatment on antibacterial and cellular response of 1393 bioactive glass (1393 BG) has been examined. The phase analyses of the sintered (at 800°C for 30min) samples revealed the formation of 1393 BG - NKN composites without any appearance of secondary phases. The addition of 10-30 vol% NKN significantly improved the mechanical behaviour of 1393 BG like, hardness (1.7 to 2 times), fracture toughness (1.3 to 2.6 times), compressive (2.3 to 8 times) and flexural strengths (2 to 3.5 times) than monolithic 1393 BG. The piezoelectric NKN is observed to induce the antibacterial activity in 1393 BG - (10- 30 vol%) NKN composites, while Staphylococcus aureus (S. aureus, gram positive) and Escherichia coli (E. coli, gram negative) bacterial cells were exposed to unpolarized and polarized (20kV, 500°C for 30min) sample surfaces. The antibacterial response was examined using disc diffusion, nitro blue tetrazolium (NBT) and MTT assays. The statistical analyses revealed the significant reduction in the viability of bacterial cells on polarized 1393 BG - (10- 30 vol%) NKN composite samples. In addition, the combined effect of electrostatic and dynamic pulsed electrical stimulation (1V/cm, 500μs pulses) on the cellular response of 1393 BG and 1393 BG - 30 vol% NKN composites has been analysed with MG-63 osteoblast-like cells. The cell proliferation was observed to increase significantly for the dynamic pulsed electric field treated negatively charged surfaces.